Infants and other incontinent individuals wear absorbent articles such as diapers to absorb and contain urine and other body exudates. Absorbent articles function both to contain the discharged materials and to isolate these materials from the body of the wearer and from the wearer's garments and bed clothing. Disposable absorbent articles having many different basic designs are known in the art. For example, U.S. Patent Re. 26,152, entitled "Disposable Diaper" issued to Duncan and Baker on Jan. 31, 1967, describes a disposable diaper which has achieved wide acceptance and commercial success. U.S. Pat. No. 3,860,003, entitled "Contractable Side Portions For Disposable Diaper", issued to Buell on Jan. 14, 1975, describes an elastic leg cuff disposable diaper which has achieved wide acceptance and commercial success.
However, absorbent articles have a tendency to sag or gap away from and to slide/slip down on the body of the wearer during use. This sagging/gapping and sliding/slipping is caused by the relative motions of the wearer as the wearer breathes, moves and changes position, by the downward forces generated when the absorbent article is loaded with body exudates, and by the deformation of the materials of the absorbent article itself when subjected to such wearer's motions. This sagging/gapping and sliding/slipping of the absorbent article can lead to premature leakage and poor fit of the absorbent article about the wearer.
Conventional disposable diapers are typically designed to fit high on the abdomen of the wearer and down on the thighs such that the diaper fits in the zones of the wearer that are subject to dynamic motion (and thus dynamic forces) during use. These dynamic motions and forces, especially by the abdomen bulging and contracting, tend to deform the materials making up the diaper and tend to push the diaper away from the body. Thus, the diaper tends to sag/gap away from the body. The closure system of the diaper is also typically designed to form a defined dimension of the waist and leg openings and a line of tension (imparts a tensile force along a line) about the wearer to secure the diaper on the wearer. However, this defined waist dimension created by the closure system cannot accommodate the changes in body dimension caused by wearer movement such that the diaper tends to slide/slip down on the wearer when the dimension of the abdomen of the wearer becomes smaller than the defined dimension formed by the closure. Further, when the abdominal dimension becomes larger than the defined dimension formed by the closure system, the body tends to push the diaper to a different position on the wearer (typically to a smaller dimension area which is lower than the point of initial fit) or the diaper tends to be so tight on the abdomen that the diaper can mark the skin or be uncomfortable to wear. Further, the absorbent core and other stiff nonelastic members of the diaper typically fit in the zones of the abdomen or legs that undergo such dynamic forces that the absorbent core is pushed downward or inward by the dynamic forces resulting in further gapping/sliding of the product on the wearer.
In order to more snugly fit absorbent articles about the wearer, certain commercially available absorbent articles have been provided with elastic features about the waist, hips, or legs. An example of a disposable diaper with an elastic waist feature which has achieved wide acceptance and commercial success is disclosed in U.S. Pat. No. 4,515,595 issued to Kievit and Osterhage on May 7, 1985. An example of a disposable diaper with an elastic leg cuff is disclosed in the previously mentioned U.S. Pat. No. 3,860,003. An example of a disposable diaper with elastic side panels to fit over the hips is disclosed in U.S. Pat. No. 4,857,067 issued to Wood, et al. on Aug. 15, 1989. The elastic features are designed to expand and contract with the wearer's motions and to maintain the fit of the absorbent article about the wearer during use (i.e., provide sustained dynamic fit).
However, it has been found that absorbent articles having elastic features also have a tendency to sag/gap and slide/slip during use.
Thus, it would be advantageous to provide an absorbent article that provides better fit, reduced leakage, and wearer comfort. It would further be advantageous to provide an absorbent article which has reduced sagging and gapping as well as reduced overall sliding/slipping of the absorbent article and/or the absorbent core on the wearer during use.
Therefore, it is an object of the present invention to provide an absorbent article having sustained dynamic fit about the wearer during use by reducing the sagging/gapping and sliding/slipping of the absorbent article on the wearer.
It is a further object of the present invention to provide an absorbent article providing increased comfort for the wearer by providing freedom of motion for the wearer and minimizing the effects of forces caused by wearer's movements on product stability.
It is also an object of the present invention to provide an absorbent article shaped to fit within the low motion zone of the wearer and/or to provide expansion of the absorbent article at those portions not fitting within the low motion zone.
It is a further object of the present invention to anchor the absorbent article about the perimeter of the low motion zone of the wearer to achieve sustained dynamic fit.
It is a still further object of the present invention to provide an absorbent article having an absorbent core shaped to fit in the low motion zone of the wearer so that the absorbent article has sustained dynamic fit during use.
It is also an object of the present invention to provide a closure system and containment assembly (chassis) design that anchor the absorbent core in the low motion zone of the wearer to enhance the sustained dynamic fit.
It is a still further object of the present invention to provide a containment assembly (chassis) design, closure system and an absorbent core shape cooperating to reduce sagging and gapping as well as overall sliding/slipping of the absorbent article during use.
These and other objects of the present invention will be more readily apparent when considered in reference to the following description and when taken in conjunction with the accompanying drawings.